2001(2):252-261.
DOI: 1
CSTR:
Abstract:
Relatively abundant and diverse nonmarine trace fossils (including small theropod dinosaur footprints) were discovered from the Early Cretaceous Laiyang Group , Laiyang Basin, eastern China. The Laiyang Group, consisting of a sequence of fluvial lacustrine strata with a thickness of 1,655 m, can be divided into six formations, which are, in ascending order, the Wawukuang, Linsishan, Zhifengzhuang, Shuinan, Longwanzhuang and Qugezhuang Formations. Eleven ichnogenera, including ten invertebrate ones and a dinosaur ichnogenus, and a type of unknown arthropod crawling trace are described in the present paper. The 10 invertebrate inchnogenera are represented by Cochlichnus anguines, Diplocraterion parallelum, Helminthoidichnites tenuis, Palaeophycus tubularis, Planolites montanus, Scolica sp., Scoyenia gracilis, Skolithos linearis, Taenidium cameronensis, Thalassinoides sp.. The dinosaur track is Paragrallator yangi Li et Zhang. Trace fossils are unevenly distributed across the section. The middle formation the Shuinan Formation, and the upper two formations the Longwangzhuang Formation and the Qugezhuang Formation yield more abundant and diverse trace fossils than the other three underlying formations. In terms of ethological classification, the trace fossils from the Laiyang Group fall in four categories, which are Domichnia (including ichnogenera Skolithos and Palaeophycus ), Repchnia (including Scolicia, the unknown arthropod trace fossil, dinosaur track Paragrallator ), Fodinichnia (ichnogenera Helmithoidichnites, Scoyenia, Taenidium, Plan olites ), and Pascichnion ( Cochlichnus ).
